py3: write out hgextindex as bytes in setup.py
I hit this trying to build the py2exe target using python3, just to see what
would happen. After commenting out `py2exe.Distribution` in setup.py and
pointing to a local copy of py2exe that supports python3[1], it complained that
`out` was bytes, not str.
[1] https://github.com/albertosottile/py2exe/releases/tag/v0.9.3.0
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.